Prove that : a cos A …
CBSE, JEE, NEET, CUET
Question Bank, Mock Tests, Exam Papers
NCERT Solutions, Sample Papers, Notes, Videos
Posted by Singh Rajput 6 years, 10 months ago
- 1 answers
Test
Related Questions
Posted by Nitin Kumar 1 year, 4 months ago
- 1 answers
Posted by Ananya Sv 1 year, 5 months ago
- 1 answers
Posted by Sana Dharwad 1 year, 4 months ago
- 0 answers
Posted by Manoj Thakur 1 year, 5 months ago
- 0 answers
Posted by Gurleen Kaur 1 year, 5 months ago
- 0 answers
Posted by Ashish Chaudhary 1 year, 4 months ago
- 1 answers
Posted by Sethpoulou Apoulou 1 year, 5 months ago
- 0 answers
Posted by Sabin Sultana 1 year, 4 months ago
- 0 answers
myCBSEguide
Trusted by 1 Crore+ Students
Test Generator
Create papers online. It's FREE.
CUET Mock Tests
75,000+ questions to practice only on myCBSEguide app
Ram Kushwah 6 years, 10 months ago
We know a / sin A = b / sin B = c / sin C.
b = a cos C + c Cos A
c = a Cos B + b cos A
LHS = a cos A + (a cos C + c cos A) cos B + (a cos B + b Cos A) cos C
= a cos A + cos A (c cos B + b Cos C) + 2 a Cos C Cos B
= a cos A + cos A * a + 2 a cos C cos B
= 2a [cos A + Cos C Cos B]
= 2 a [ cos (π-B-C) + cos C cos B]
= 2 a [- cos (B+C) + cos C cos B]
= 2 a Sin B sin C
Read more on Brainly.in - https://brainly.in/question/1122558#readmore
1Thank You